Facsimile wet electrolytic recording



Patented Oct. 2, 1951 r FACSIMILE WET ELECTROLYTIC RECORDING Frank G. Calkin, Glen Rock, N. J., assignor, by

mesne assignments, to Pierce Company, Providence, R. I.

No Drawing. Application January 9, 1947, Serial No. 721,164

1 Claim. 1

My invention relates to a recording paper particularly adapted for use in connection with the wet electrolytic method of facsimile recording which utilizes a high wet strength paper or other suitable base impregnated with a water solution which is conductive in order to permit current to pass therethrough and which is also discolorable at the passage of electric current therethrough in order to make a record in accordance with received facsimile impulses.

One type of apparatus in connection with which my wet electrolytic recording paper may be utilized is shown in Patent No. 2,413,962.

A primary object of my invention is to include in the water solution which is utilized to impregnate the Wet electrolytic recording paper a water-soluble salt of manganese, a persulfate, and one or more alkali metal salts.

The foregoing and many other objects of my invention will appear in the following description:

Essentially, as above pointed out, my invention depends on a combination in the solution of (a) A water-soluble salt of manganese (b) A persulfate One or more alkali metal salts A typical solution in accordance with the foregoing prerequisites is:

Manganous sulfate grams 456 Ammonium persulfate do 456 Sodium chloride do 500 Sodium nitrate do 500 Distilled water to make liters 20 The above solution may contain manganese sulfate, ammonium persulfate, sodium chloride and sodium nitrate in relative proportions of about 9, 9, and 10 parts by weight, respectively. This solution has been found to be extremely satisfactory, both in the manner in which it conducts electric current therethrough and also in the manner in which it discolors to produce a facsimile record.

In the utilization of a recording medium of this type, I depend upon the chemical reaction between manganese salts and persulfates in alkaline solution to produce the black compound, manganese dioxide, upon the paper in the image of the material transmitted.

As prepared, the impregnated paper is neutral 2 to slightly acid. Upon passage of an electric current through the paper, however, sufficient alkalinity is produced through electrolysis of the alkali metal salts in the impregnating solution to give the characteristic persulfate reaction with the manganese salt.

In addition to providing a source of the required alkalinity at the time of marking, the alkali metal salt or salts included in the impregnating solution serve to increase the electrical conductivity of the paper to the desired degree.

In the foregoing I have described my invention solely in connection with a specific preferred embodiment thereof. Since many variations and modifications of my invention should now be obvious to those skilled in the art, I prefer to be bound not by the specific disclosure herein contained, but only by the appended claim.

I claim:

A wet electrolytic facsimile recording paper impregnated with a solution consisting essentially of a water solution of water soluble manganous sulphate, ammonium persulfate, sodium chloride and sodium nitrate in relative proportions of about 9, 9, 10 and 10 parts by weight, respectively, and adapted to be discolored by the passage of electric current therethrough.

FRANK G. CALKIN'.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 6,420 Morse May 1, 1849 160,404 Edison Mar. 2, 1875 1,055,157 French Mar. 4, 1913 1,844,199 Bicknell Feb. 9, 1932 1,850,600 Morehouse Mar. 22, 1932 1,880,449 Hickman et al. Oct. 4, 1932 2,119,560 Shelton June 7, 1938 2,225,247 Kline Dec. 17, 1940 OTHER REFERENCES A Comprehensive Treatise on Inorganic and Theoretical Chemistry, volume X; J. W. Mellor, 1930, page 480. 

